The scientific study of the harmful effects of indoor fires on building structures and on the environment is a top issue today. Indoor fires frequently occur all over the world. The goal of our research is to examine the effects of an average room fire on the survival possibility of a trapped person and on the building structure, taking into account features of the Eastern European architecture. First, a computational fluid dynamics (CFD) simulation was performed to examine the change of temperature, oxygen, and carbon monoxide concentration in a selected room in a vacant building used for military training. Based on the results, a 1:1 scale fire experiment was carried out with the parameters used in the simulation. The experiment was repeated once with the same settings. It was observed that without the intervention of firefighters, the temperature in the experiment could have rapidly reached 400 °C, as suggested by the simulation, which could have caused structural damage to the building. Furthermore, after 3 min the carbon monoxide concentration reached 400 ppm in both experiments and the simulation, which is a harmful level to people trapped inside the room. Also, in the experiment there was sufficient oxygen at the ground level with what people can survive 3 min.

Closed-space fires often occur in Hungary, so it is necessary to examine the effects of fires on building structures, taking into account Hungarian architectural features. Fires inside the buildings are characterized by intense heat development and smoke generation that can cause permanent damage to the building structures. Heat and smoke extraction during fire extinguishing is based usually on natural ventilation. Not only being a non-effective process also makes it more difficult to accomplish firefighting tasks. Experiments in this research have been conducted with mobile positive pressure ventilation (PPV) in order to increase the efficiency of the firefighting process and to reduce the adverse effects of fires. The tests have been carried out in unused buildings, providing real conditions. Practical application has been examined in order to reduce the harmful effects of closed-space fires and to provide guidance for professional use. This research based on observations and experiments contributes to enhancing fire safety.